#define _CRT_SECURE_NO_WARNINGS 1
int climbStairs(int n) {
    if (n < 2)
        return 1;
    int* dp = (int*)malloc(sizeof(int) * (n + 1));
    dp[0] = 1;
    dp[1] = 1;
    for (int i = 2; i <= n; i++)
        dp[i] = dp[i - 1] + dp[i - 2];
    return dp[n];
}